# Lean-ctx

> **TL;DR.** [Lean-ctx](https://leanctx.

- **Category:** AI / Developer Tools / Infrastructure
- **Stage:** rising
- **Age:** 103 days
- **Origin date:** 2026-03-23
- **First detected:** 2026-06-05
- **Canonical URL:** https://earlyterms.com/term/lean-ctx
- **Sources:** 7 primary URLs

## Definition

[Lean-ctx](https://leanctx.com) (LeanCTX) is a local-first context intelligence layer for AI coding agents: a single Rust binary and MCP server that decides what a model reads, remembers, and is allowed to touch, compressing file reads and shell output by a claimed 60-90% before they burn tokens.

Solo developer Yves Gugger opened the [yvgude/lean-ctx](https://github.com/yvgude/lean-ctx) repo on March 23, 2026, and shipped over 225 releases in three months, crossing 3,000 GitHub stars and adding Claude Code, Cursor, and Copilot support — while a June 2026 external audit found it forwarded API keys to shell children, patched within days.

## Analogy

Think of it as a customs agent at your codebase's border, inspecting every file crossing over and issuing a receipt for what it stopped.

## Why it's emerging now

A solo-built Rust binary crossed 3,000 GitHub stars and 225 releases in just over 100 days, becoming a reference point for the "token-tax" tooling race alongside Headroom and RTK. An independent tokbench audit in June found lean-ctx billed 38-59% more tokens than native, not fewer, while a separate external security audit caught it forwarding API keys to shell children.

## Related terms

- *parent:* Context Engineering
- *related:* MCP Server
- *related:* MCP Tool
- *related:* Model Context Protocol
- *related:* Context Window
- *related:* Context Rot
- *related:* RLMs
- *related:* Claude Code
- *competitor:* Headroom
- *competitor:* RTK
- *competitor:* MemGPT

## Sources

1. [yvgude/lean-ctx — GitHub repository](https://github.com/yvgude/lean-ctx)
2. [LeanCTX — official site](https://leanctx.com/)
3. [LeanCTX — Compare vs. Headroom, RTK, MemGPT](https://leanctx.com/compare/)
4. [lean-ctx CHANGELOG](https://github.com/yvgude/lean-ctx/blob/main/CHANGELOG.md)
5. [v3.8.12 release notes — external audit hardening](https://github.com/yvgude/lean-ctx/releases/tag/v3.8.12)
6. [Entelligentsia/tokbench — independent token-billing audit](https://github.com/Entelligentsia/tokbench)
7. [andrew.ooo — Headroom Review (compares lean-ctx)](https://andrew.ooo/posts/headroom-context-compression-llm-agents-review/)

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_Generated by EarlyTerms · https://earlyterms.com/term/lean-ctx_